The present invention relates generally to airborne radar tracking systems, and specifically to a modification of such systems to provide a simultaneous search/target track capability.
The AN/APG-66 radar was deployed during the late 1970's on F-16 fighter aircraft. At that time single target track was considered to be the primary weapon release mode. The typical engagement was one F-16 against one enemy aircraft, and the missiles used were relatively short range. Once the high priority target was selected for attack, full concentration of radar power was applied to complete the engagement.
Tactics have changed since that time. One-on-one attack is no longer a viable possibility and concentrating full radar energy on a single target blinds the F-16 to other targets and exposes it to counter attack by the remainder of the enemy formation. Newer long range missiles are being developed which make it possible to attack at longer ranges but current radar technology will not support them.
The task of providing fighter aircraft with the ability to simultaneously track a target and sense other approaching aircraft is alleviated, to some extent, by the following U.S. Patents, which are incorporated herein by reference:
U.S. Pat. No. 3,064,250 issued to Close on Nov. 13, 1962;
U.S. Pat. No. 3,267,323 issued to Gerwin on Aug. 16, 1966;
U.S. Pat. No. 3,699,573 issued to Andrews et al on Oct. 17, 1972; and
U.S. Pat. No. 3,987,440 issued to Danzer on Oct. 19, 1976.
The Andrews, Danzer and Close references all disclose track-while-scan (TWS) radar systems. Andrews et al are concerned with a track-while-scan radar that initiates tracking of a target on the basis of previous position information or plots stored in a computer memory. This reference discloses a system in which the actual updating of the target's position is automatically performed by the computer, and the decision to track a given target is manually performed by an operator observing a target position display console. In Danzer "sliding window" computer processing is used with a system that tracks the target while scanning of an entire sector area continues. The Close track-while-scan channel automatically alters its operating parameters to fit the tracking conditions which exist at the moment. Gerwin is directed to a single servo multiple target automatic tracking circuit. The Gerwin device operates on time sharing principles.
These TWS systems are alternatives which may be substituted in place of the existing radar used by the F-16 TWS systems are capable of providing track quality information on up to 10 targets within the radar field of view. Counter attacks on the F-16 by the enemy formation are minimized and the deployment of AMRAAM missiles allows for multiple launches at long ranges.
TWS systems have been proposed and are under development for use by the U.S. Air Force as substitute systems to the single target track radar systems currently used. However, an alternative to replacing existing APG-66 radars and other inexpensive systems, which are currently in the U.S. arsenal, is modifying existing systems to provide them with a simultaneous search/track capability.
In view of the foregoing discussion, it is apparent that there currently exists the need for a modification of existing radar systems so that they are capable of detecting the presence of other aircraft while tracking a selected target The present invention is intended to satisfy that need.